Impact of Left Atrial Appendage Flow Velocity on Thrombus Resolution and Clinical Outcomes in Patients with Atrial Fibrillation and Silent Left Atrial Thrombi: Insights from the LAT Study

Overview

Journal Europace

Publisher Oxford University Press

Specialties Cardiology & Vascular Diseases
Physiology

Date 2024 May 1

PMID 38691672

Authors

Masato Okada

Koichi Inoue

Nobuaki Tanaka

Koji Tanaka

Yuko Hirao

Katsuomi Iwakura

Yasuyuki Egami

Masaharu Masuda

Tetsuya Watanabe

Hitoshi Minamiguchi

Takafumi Oka

Shungo Hikoso

Akihiro Sunaga

Katsuki Okada

Daisaku Nakatani

Yohei Sotomi

Yasushi Sakata

Affiliations

Soon will be listed here.

Abstract

Aims: Blood stasis is crucial in developing left atrial (LA) thrombi. LA appendage peak flow velocity (LAAFV) is a quantitative parameter for estimating thromboembolic risk. However, its impact on LA thrombus resolution and clinical outcomes remains unclear.

Methods And Results: The LAT study was a multicentre observational study investigating patients with atrial fibrillation (AF) and silent LA thrombi detected by transoesophageal echocardiography (TEE). Among 17 436 TEE procedures for patients with AF, 297 patients (1.7%) had silent LA thrombi. Excluding patients without follow-up examinations, we enrolled 169 whose baseline LAAFV was available. Oral anticoagulation use increased from 85.7% at baseline to 97.0% at the final follow-up (P < 0.001). During 1 year, LA thrombus resolution was confirmed in 130 (76.9%) patients within 76 (34-138) days. Conversely, 26 had residual LA thrombi, 8 had thromboembolisms, and 5 required surgical removal. These patients with failed thrombus resolution had lower baseline LAAFV than those with successful resolution (18.0 [15.8-22.0] vs. 22.2 [17.0-35.0], P = 0.003). Despite limited predictive power (area under the curve, 0.659; P = 0.001), LAAFV ≤ 20.0 cm/s (best cut-off) significantly predicted failed LA thrombus resolution, even after adjusting for potential confounders (odds ratio, 2.72; 95% confidence interval, 1.22-6.09; P = 0.015). The incidence of adverse outcomes including ischaemic stroke/systemic embolism, major bleeding, or all-cause death was significantly higher in patients with reduced LAAFV than in those with preserved LAAFV (28.4% vs. 11.6%, log-rank P = 0.005).

Conclusion: Failed LA thrombus resolution was not rare in patients with AF and silent LA thrombi. Reduced LAAFV was associated with failed LA thrombus resolution and adverse clinical outcomes.

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